Alkaline liquid hard surface cleaning compositions are well known in the art. The alkalinity provides improved grease cleaning properties but typically is employed in conjunction with other components which require careful rinsing of the cleaned surface before this surface could be used in any direct contact with items intended for ingestion by humans or lower animals. Conventional hard surface cleaners typically include inorganic and organic compounds which would be unacceptable if transferred to foods which contact the cleansed surface. Some cleaners employ bleaching agents, abrasives, and/or solvents which could also negatively impact food items.
Another consideration on formulation of hard surface cleaners, particularly those not intended to be thoroughly rinsed off after use, is the film/streak performance after wiping and drying of the cleaner on the surface. It is well known that liquid cleaning compositions, and especially compositions prepared for cleaning glass and kitchen tile, need exceptionally good filming/streaking properties. Because good filming/streaking properties are required especially for these cleaners, the levels of surfactants and other actives must be kept low in order to achieve this benefit. Such compositions frequently rely on the use of ammonia and strong organic solvents to achieve good results.
It will be appreciated that the formulation of truly effective compositions, especially those which can be used safely by individual consumers, for washing hard surfaces presents a unique problem to the formulator, inasmuch as many art-disclosed cleaning ingredients would, presumably, not be desirable for use in direct contact with foods where they might not be fully removed.
Moreover, it would be especially desirable to provide effective, toxicologically-acceptable cleaning compositions for hard surfaces in the form of substantially low-sudsing liquid solutions which are clear or which have only minimal haziness. Liquid solutions are convenient for the user, since they can be applied directly to hard surfaces, followed by wiping. The clarity of the liquids connotes cleanliness to the user and is thus highly desirable. Low sudsing is an important attribute so that removal of the solution by wiping is achieved quickly and easily. It would also be of advantage if such compositions could be provided in the form of concentrates, which could be diluted by the consumer before use and/or applied to the surfaces as a direct spray-on.
Unfortunately, many toxicologically-acceptable cleaning ingredients do not meet the aforesaid requirements for clear, low-sudsing, dilutable liquid products. Many detersive surfactants form cloudy or even opaque suspensions in water. Of course, many surfactants are specifically designed to be high sudsing. Still others form relatively intractable phases in their concentrated form.
It has now been discovered that certain anionic and nonionic surfactants, properly formulated with other ingredients can provide liquid compositions having the desired properties described above.